Scientists at Colossal Biosciences say they have created three dire-wolf pups by using ancient DNA and cloning technology to alter the genes of a grey wolf, the dire wolf’s closest living relative. The pups are effectively a hybrid species similar in appearance to its extinct predecessor.

“Our team took DNA from a 13,000-year-old tooth and a 72,000-year-old skull and made healthy dire-wolf puppies,” Colossal said in a news release.

To accomplish this, the company essentially created a hybrid genome to cut away certain grey-wolf gene variants and replace them with traits associated with dire wolves. The result is three “resurrected” dire wolves – or something close to it.

Two male pups were born last Oct 1, while a female pup was born on Jan 30, the firm added.

Once a top predator that roamed North America, the dire wolf – “Aenocyon dirus” – was the inspiration for the fearsome canine that featured in the hit TV show “Game of Thrones”.

Two of the pups, Romulus and Remus, are named after the mythical founders of Rome, who were raised by a wolf. The third pup, Khaleesi, is named after a leading character in the HBO series.

Colossal had previously disclosed it had been working towards bringing back the mammoth, dodo, and Tasmanian Tiger. This is the first time it has revealed its work on dire wolves.

The three wolf pups are reportedly living on an 809ha site at an undisclosed location enclosed by 3m-tall “zoo-grade” fencing, where they are monitored by security personnel, drones, and live camera feeds.

Colossal hopes the same technologies that created the dire wolf can also help endangered animals, saying on Monday it has produced two litters of cloned red wolves, the most critically endangered wolf species.